#data
<isindex>
#errors
(1,9): expected-doctype-but-got-start-tag
(1,9): deprecated-tag
#document
| <html>
|   <head>
|   <body>
|     <form>
|       <hr>
|       <label>
|         "This is a searchable index. Enter search keywords: "
|         <input>
|           name="isindex"
|       <hr>

#data
<isindex name="A" action="B" prompt="C" foo="D">
#errors
(1,48): expected-doctype-but-got-start-tag
(1,48): deprecated-tag
#document
| <html>
|   <head>
|   <body>
|     <form>
|       action="B"
|       <hr>
|       <label>
|         "C"
|         <input>
|           foo="D"
|           name="isindex"
|       <hr>

#data
<form><isindex>
#errors
(1,6): expected-doctype-but-got-start-tag
(1,15): deprecated-tag
(1,15): expected-closing-tag-but-got-eof
#document
| <html>
|   <head>
|   <body>
|     <form>

#data
<body><isindex><form>
#errors
6: Start tag seen without seeing a doctype first. Expected “<!DOCTYPE html>”.
15: “isindex” seen.
21: End of file seen and there were open elements.
21: Unclosed element “form”.
#document
| <html>
|   <head>
|   <body>
|     <form>
|       <hr>
|       <label>
|         "This is a searchable index. Enter search keywords: "
|         <input>
|           name="isindex"
|       <hr>
|     <form>
